DOCSLIB.ORG

Cenozoic Incision History of the Little Colorado River: Its Role in Carving Grand Canyon and Onset of Rapid Incision in the Past GEOSPHERE; V

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Cenozoic Incision History of the Little Colorado River: Its Role in Carving Grand Canyon and Onset of Rapid Incision in the Past GEOSPHERE; V Research Paper THEMED ISSUE: CRevolution 2: Origin and Evolution of the Colorado River System II GEOSPHERE Cenozoic incision history of the Little Colorado River: Its role in carving Grand Canyon and onset of rapid incision in the past GEOSPHERE; v. 13, no. 1 ca. 2 Ma in the Colorado River System doi:10.1130/GES01304.1 K.E. Karlstrom1, L.J. Crossey1, E. Embid1, R. Crow2, M. Heizler3, R. Hereford2, L.S. Beard2, J.W. Ricketts4, S. Cather3, and S. Kelley3 18 figures; 1 table; 1 supplemental file 1Department of Earth and Planetary Sciences, University of New Mexico, MSC03-2040, University of New Mexico, Albuquerque, New Mexico 87131-0001, USA 2U.S. Geological Survey, 2255 N. Gemini Drive, Flagstaff, Arizona 86001, USA 3New Mexico Bureau of Geology & Mineral Resources–New Mexico Institute of Mining & Technology, 801 Leroy Place, Socorro, New Mexico 87801, USA CORRESPONDENCE: kek1@ unm .edu 4Department of Geological Sciences, University of Texas at El Paso, El Paso, Texas 79968, USA CITATION: Karlstrom, K.E., Crossey, L.J., Embid, E., Crow, R., Heizler, M., Hereford, R., Beard, L.S., Ricketts, J.W., Cather, S., and Kelley, S., 2017, Ce- ABSTRACT for LCR and CR incision studies. Post–2 Ma differential incision magnitudes nozoic incision history of the Little Colorado River: (and rates) in the lower LCR and at the LCR-CR confluence were 280–320 m Its role in carving Grand Canyon and onset of rapid This paper documents a multi-stage incision and denudation history for (140–160 m/Ma), about three times greater than the 40–80 m (20–40 m/Ma) in incision in the past ca. 2 Ma in the Colorado River System: Geosphere, v. 13, no. 1, p. 49–81, doi: 10 .1130 the Little Colorado River (LCR) region of the southwestern Colorado Plateau the LCR headwaters. /GES01304.1. over the past 70 Ma. The first two pulses of denudation are documented by The proposed mechanisms driving overall post–6 Ma differential inci- thermochronologic data. Differential Laramide cooling of samples on the sion of the LCR involve headwater uplift associated with the Hopi Buttes Received 14 December 2015 Mogollon Rim suggests carving of 70–30 Ma paleotopography by N- and and Springer ville volcanic fields plus base-level fall caused by CR integration Revision received 10 August 2016 E-flowing rivers whose pathways were partly controlled by strike valleys at to the Gulf of California. A proposed mechanism to explain the accelerated Accepted 4 November 2016 Final version published online 10 January 2017 the base of retreating Cretaceous cliffs. A second pulse of denudation is docu- post–2 Ma differential incision in the central and lower LCR valley, but not in mented by apatite (U-Th)/He dates and thermal history models that indicate a the head waters, involves mantle-driven epeirogenic uplift due to NE-migrat- broad LCR paleovalley was incised 25–15 Ma by an LCR paleoriver that flowed ing vol canism associated with the San Francisco volcanic field. Tectonically northwest and carved an East Kaibab paleovalley across the Kaibab uplift. driven differential surface uplift mechanisms were likely amplified by changes Lacustrine strata of the lower Bidahochi Formation were deposited 16– toward more erosive climate at ca. 6 Ma and ca. 2 Ma. 14 Ma in the LCR paleovalley in a closed basin playa or marsh with a valley center near the modern LCR. There is a hiatus in the depositional record in the LCR valley from 12 to 8 Ma followed by aggradation of the 8–6 Ma fluvial upper INTRODUCTION Bidahochi Formation. Interlayered 8–6 Ma maar basalts that interacted with groundwater mark local base level for upper Bidahochi fluvial deposits; this Little Colorado River (LCR) is one of the largest drainage basin area tribu- was also a time of increased groundwater flow to Hualapai Limestone at the taries to Colorado River (CR). As shown in Figure 1, its headwaters are in the western edge of the Colorado Plateau. The paleo–base level in the central LCR White Mountains and Springerville volcanic field at the southern edge of the valley remained stable (~1900 m modern elevation) from 16 to 6 Ma. Colorado Plateau. It flows in a broad valley across highly erodible Mesozoic The third pulse of regional incision and denudation, most recent and ongo- strata of the Holbrook and Winslow areas, enters a deep bedrock gorge in ing, started after integration of the Colorado River (CR) through Grand Canyon. Paleozoic rocks near Cameron, and has its confluence with the CR in Grand Thermochronology from Marble Canyon indicates that early CR integration Canyon 62 river miles below Lees Ferry (Stevens, 1983). Its modern river pro- took place across the Vermillion Cliffs at Lees Ferry after 6 Ma. The elevation of file is plotted along with the CR profile in Figure 2. The LCR profile departs from the paleoconfluence between the LCR and CR at 5–6 Ma is poorly constrained, a concave-up “equilibrium” profile in its lower and upper reaches; the lower but earliest CR integration is hypothesized to have reoccupied the East Kai- 75 km has a convex-up steepened reach in resistant Paleozoic rocks below a bab paleocanyon. In the upper LCR drainage, topographically inverted basalt knickpoint (LCR knickpoint). It also has sharp bedrock knickpoints including mesas have elevations and K-Ar dates indicating a transition from aggradation a ca. 20 ka basalt flow at Grand Falls (Duffield et al., 2006) and several knick- to incision ca. 6 Ma followed by semi-steady incision of 20–40 m/Ma. In the points in basalts in the headwater regions. lower LCR, incision accelerated to 120–170 m/Ma after 2 Ma as indicated by The overall goal of this study is to understand linkages between the Little For permission to copy, contact Copyright 40Ar/39Ar dating of basalt, ash-fall, and detrital sanidine. A 1.993 ± 0.002 Ma Colorado River and Colorado River systems and their influence on carving Permissions, GSA, or [email protected]. sanidine age for a tuff in the White Mesa alluvium provides a breakthrough Grand Canyon and to test models for landscape evolution in the region. We © 2016 Geological Society of America GEOSPHERE | Volume 13 | Number 1 Karlstrom et al. | Rapid incision in Little Colorado River in past 2 Ma Downloaded from http://pubs.geoscienceworld.org/gsa/geosphere/article-pdf/13/1/49/1000756/49.pdf 49 by guest on 29 September 2021 Research Paper r San Juan Ri Rive 37° N Virgin ver ? V WM Kaibab 2B B San SV uplift 2A 4 Juan K 15A Figure 1. Map of the Grand Canyon region G C Basin 1 at ca. 15 Ma. Locations and extent of 15 Ma !5 S M NE !3 (1 Hopi paleolake-marsh is based on pres- (!4 Little Colorado 36° N (!2 ent elevations of the 15.8–13.6 Ma lower E 3 RB (! 7 (lacus trine) Bidahochi Formation; orange !N CA outcrops are upper (fluvial) Bidahochi For- (!F C 5 1900 m (! mation. Numbered incision points (yellow G 6 Pale (!A 10 stars) are keyed to Table 1; key thermo- !J Little Colora ori 11 M 15 ver chronology samples (red) are keyed to sec- ogollo 9 Highland tion DR-2 (see footnote 1); rim (green) and Mogollon Slop river (purple) thermochronologic samples n 12 W Hopi do Rive Paleo lake document East Kaibab paleocanyon (Karl- 35° N s (!B H 15 Ma 8 strom et al., 2014). Cross section location Springerville 13 r (!C for Figure 9 is shown. Red dashed line is volcanic eld (!I e axis of ca. 2 Ma White Mesa paleovalley. 14 18 Valencia surface (!L (!D 19 30 B—Black Mesa; C—Chuska Mountains; 00 SJ CA—Cameron; G—Gap; H—Holbrook; (!K 35 44 (! LCR thermochronology (!M (! M—Moenkopi Wash; MB—Mount Baldy; A samples H 16 34 RB—Red Butte basalt; SJ—St. Johns; SW SP SP—Springerville; SV—Shivwits basalt 34° N 1 LCR incision points on Grassy Mountain; V—Vermillion Cliffs; MB WM—White Mesa; W—Winslow. Contoured base of Salt River 1830 Bidahochi Fm. (m) 1900 N r 0525 0100 150200 Gila Rive km 33° N 114° W 113° W 112° W111° W110° W109° W synthesize new and published data on the incisional history of the LCR region incision magnitudes. However, it is probable that both relative and absolute over the past 70 Ma and present the following data sets. (1) HeFTy modeling of elevations have changed due to differential surface uplift (Hunt, 1969, p. 113) low-temperature thermochronology data (from Flowers et al., 2008) provides resulting from a combination of changes in mantle buoyancy (Karlstrom et al., constraints on the 70–15 Ma denudation episodes. (2) Data on the Bidahochi 2008, 2011; Crow et al., 2014), fault dampened incision (Pederson et al., 2002; Formation and associated volcanic rocks (Dallegge et al., 2001; Dickinson, 2013) Karlstrom et al., 2007), and isostatic rebound due to differential erosion (Lazear provide a record of the 16–6 Ma time interval. (3) Incision rate data over the et al., 2013). past 7 Ma are derived from 40Ar/39Ar plus older K-Ar ages of basalt surfaces that form inverted topography and/or overlie gravel terraces in the LCR and its tributaries (Damon and Spencer, 2001; Holm, 2001a). (4) We also add 40Ar/39Ar ANNOTATED HISTORICAL BACKGROUND detrital-sanidine dates on elevated surfaces (Cooley et al., 1969) and paleoriver deposits (Hereford et al., 2016). (5) For the past 1 Ma, we report new 40Ar/39Ar Powell (1879) had little scientific comment on the LCR. Dutton (1882, p. 204) dates on basalts that entered the paleo-LCR channel and U-series dates on trav- thought it was as “old as the Colorado River itself” and viewed it as early ertine-cemented CR and LCR gravel terraces (Embid, 2009; Crow et al., 2014).
Load more

Recommended publications
  • Narbonapass.Pdf
    FIRST-DAY ROAD LOG 1 FIRST-DAY ROAD LOG, FROM GALLUP TO GAMERCO, YAH-TA-HEY, WINDOW ROCK, FORT DEFIANCE, NAVAJO, TODILTO PARK, CRYSTAL, NARBONA PASS, SHEEP SPRINGS, TOHATCHI AND GALLUP SPENCER G. LUCAS, STEVEN C. SEMKEN, ANDREW B. HECKERT, WILLIAM R. BERGLOF, First-day Road Log GRETCHEN HOFFMAN, BARRY S. KUES, LARRY S. CRUMPLER AND JAYNE C. AUBELE ������ ������ ������ ������� ������ ������ ������ ������ �������� Distance: 141.8 miles ������� Stops: 5 ���� ������ ������ SUMMARY ������ �� ������ �� ����� �� The first day’s trip takes us around the southern �� �� flank of the Defiance uplift, back over it into the �� southwestern San Juan Basin and ends at the Hogback monocline at Gallup. The trip emphasizes Mesozoic— especially Jurassic—stratigraphy and sedimentation in NOTE: Most of this day’s trip will be conducted the Defiance uplift region. We also closely examine within the boundaries of the Navajo (Diné) Nation under Cenozoic volcanism of the Navajo volcanic field. a permit from the Navajo Nation Minerals Department. Stop 1 at Window Rock discusses the Laramide Persons wishing to conduct geological investigations Defiance uplift and introduces Jurassic eolianites near on the Navajo Nation, including stops described in this the preserved southern edge of the Middle-Upper guidebook, must first apply for and receive a permit Jurassic depositional basin. At Todilto Park, Stop 2, from the Navajo Nation Minerals Department, P.O. we examine the type area of the Jurassic Todilto For- Box 1910, Window Rock, Arizona, 86515, 928-871- mation and discuss Todilto deposition and economic 6587. Sample collection on Navajo land is forbidden. geology, a recurrent theme of this field conference. From Todilto Park we move on to the Green Knobs diatreme adjacent to the highway for Stop 3, and then to Stop 4 at the Narbona Pass maar at the crest of the Chuska Mountains.
    [Show full text]
  • George H. Davis — Curriculum Vita
    George H. Davis — Curriculum Vita Contents 1 Personal……………………………………………………………………………. .1 2 Education, Degrees, and Theses…………………………………………………… 1 3 Appointments………………………………………………………………………. .2 4 Early Geologic Field Experience………………………………………………… . .2 5 Current Research Projects…………………………………………………………. .3 6 Main courses taught in Geosciences ……………………………………………… 3 7 Honors, Awards, and Special Recognition or Service…………………………….. 4 8 Professional Services and Activities………………………………………………. 6 9 Venues of Invited Lecture Presentations…………………………………………. 14 10 Publications: Books ………………………………………..................................... 14 11 Publications: Peer-Reviewed Articles and Maps………………………………… 15 12 Publications: Abstracts……………………………………………………………. 21 13 Publications: Miscellaneous………………………………………………………. 28 14 Sponsored Research……………………………………………………………..... 30 15 Graduate Theses and Dissertations Supervised………………………………….. 32 16 Graduate Students for whom Davis Served as Research Committee Member…… 34 17 Undergraduate Research Advisees………………………………………………… 35 18 Administrative Leadership and Service: The University of AriZona………………35 19 Administrative Service: The University of Vermont……………………………….38 1 Personal George H. Davis Regents Professor Emeritus & Provost Emeritus Department of Geosciences, The University of AriZona 326 Gould-Simpson Building Tucson, AriZona 85721 (520) 349-2622 (cell) [email protected] 2 Education, Degrees, Theses 1964, B.A., with honors, Geology, The College of Wooster, Wooster, Ohio Davis, G.H., 1964, Application of graphic
    [Show full text]
  • Curriculum Vita - Stephen J
    Curriculum Vita - Stephen J. Reynolds School of Earth and Space Exploration, Arizona State University, Tempe, Arizona 85287-1404 (480) 965-9049 (work) Website: http://reynolds.asu.edu email: [email protected] Degrees/Registration University of Texas, El Paso: B.S., Geology, 1974 University of Arizona: M.S., Geosciences, 1977, Ph.D., Geosciences,1982 Arizona Registered Geologist #26773 (1993-present) Recent Professional Experience Arizona State University, Dept. of Geology: Professor (6/97 to present), Associate Professor (8/91 to 6/97). Teaching responsibilities include Advanced Geologic Field Mapping, Advanced Structural Geology, Applied Arizona Geology, Cordilleran Regional Geology, Geology of Arizona, Geotectonics, Introductory Geology, Orogenic Systems, Summer Field Geology, Methods of Geoscience Teaching ASU Center for Research on Education in Science, Mathematics, Engineering, and Technology, Associate Director (6/99 to present); chairman of founding committee. Arizona Geological Survey and Arizona Bureau of Geology and Mineral Technology: Research Geologist (6/88 to 7/91), Associate Research Geologist (6/87 to 6/88); Assistant Research Geologist (2/81 to 6/87). University of Arizona, Dept. of Geosciences: Visiting Associate Professor, (1991 to ~1997); Adjunct Associate Research Scientist (1987 to 1991); Research Associate and Assistant (1/75 to 12/80); Teaching Assistant (8/74 to 7/75) Geologist and Consulting Geologist: Clients include Animas Resources (2007 to present), Pediment Exploration, Ltd. (2007 to present), Clear Creek
    [Show full text]
  • Arizona Forest Action Plan 2015 Status Report and Addendum
    Arizona Forest Action Plan 2015 Status Report and Addendum A report on the strategic plan to address forest-related conditions, trends, threats, and opportunities as identified in the 2010 Arizona Forest Resource Assessment and Strategy. November 20, 2015 Arizona State Forestry Acknowledgements: Arizona State Forestry would like to thank the USDA Forest Service for their ongoing support of cooperative forestry and fire programs in the State of Arizona, and for specific funding to support creation of this report. We would also like to thank the many individuals and organizations who contributed to drafting the original 2010 Forest Resource Assessment and Resource Strategy (Arizona Forest Action Plan) and to the numerous organizations and individuals who provided input for this 2015 status report and addendum. Special thanks go to Arizona State Forestry staff who graciously contributed many hours to collect information and data from partner organizations – and to writing, editing, and proofreading this document. Jeff Whitney Arizona State Forester Granite Mountain Hotshots Memorial On the second anniversary of the Yarnell Hill Fire, the State of Arizona purchased 320 acres of land near the site where the 19 Granite Mountain Hotshots sacrificed their lives while battling one of the most devastating fires in Arizona’s history. This site is now the Granite Mountain Hotshots Memorial State Park. “This site will serve as a lasting memorial to the brave hotshots who gave their lives to protect their community,” said Governor Ducey. “While we can never truly repay our debt to these heroes, we can – and should – honor them every day. Arizona is proud to offer the public a space where we can pay tribute to them, their families and all of our firefighters and first responders for generations to come.” Arizona Forest Action Plan – 2015 Status Report and Addendum Background Contents The 2010 Forest Action Plan The development of Arizona’s Forest Resource Assessment and Strategy (now known as Arizona’s “Forest Action Plan”) was prompted by federal legislative requirements.
    [Show full text]
  • Mountains, Streams, and Lakes of Oklahoma I
    Information Series #1, June 1998 Mountains, Streams, and Lakes of OklahomaI Kenneth S. Johnson2 INTRODUCTION valleys, hills, and plains throughout most of the re­ mainder of Oklahoma (Fig. 1). All the major lakes and Mountains and streams define the landscape of reservoirs of Oklahoma are man-made, and they are Oklahoma (Fig. 1). The mountains consist mainly of important for flood contr()l, water supply, recreation, resistant rock masses that were folded, faulted, and and generation of hydroelectric power. Natural lakes thrust upward in the geologic past (Fig. 2), whereas in Oklahoma are limited to oxbow lakes along major the streams have persisted in eroding less-resistant streams and to playa lakes in the High Plains region rock units and lowering the landscape to form broad of the west. Alphabetical List of20 Lakes with Largest Surface Area (from Oklahoma Water Atlas, Oklahoma Water Resources Board) 1. Broken Bow 11. Lake 0' The Cherokees 2. Canton 12. Oologah 3. Eufaula 13. Robert s. Kerr 4. Fort Gibson 14. Sardis 5. Foss 15. Skiatook 6. Great Salt Plains 16. Tenkiller Ferry ·7. Hudson 17. Texoma 8. Hugo 18. Waurika 9. Kaw 19. Webbers Falls 10. Keystone 20. Wister Modified from Historical Atlas of Oklahoma, by John W. Morris, Charles R. Goins, and Edwin C. 25 McReynolds. Copyright © 1986 by the University I of Oklahoma Press. o 40 80Km Figure 1. Mountains, streams, and principal lakes of Oklahoma. lReprinted from Oklahoma Geology Notes (1993), vol. 53, no. 5, p. 180-188. The Notes article was reprinted and expanded from Oklahoma Almanac, 1993-1994, Oklahoma Department of Lihraries, p.
    [Show full text]
  • Canyon's 'Guardians' Press for Protections by Matthew Putesoy - Jul
    THE ARIZONA REPUBLIC Canyon's 'guardians' press for protections by Matthew Putesoy - Jul. 25, 2009 My Turn The Grand Canyon is a national treasure, inviting 5 million people every year to explore and be inspired by its beauty. To the Havasuw 'Baaja, who have lived in the region for many hundreds of years, it is sacred. As the "guardians of the Grand Canyon," we strenuously object to mining for uranium here. It is a threat to the health of our environment and tribe, our tourism-based economy, and our religion. Thank you, Secretary of Interior Ken Salazar, for announcing a two-year moratorium on new mining claims in the 1 million acres of lands around Grand Canyon National Park. But existing claims, such as those pursued by Canadian-based Denison Mines Corp., still threaten the animals, air, drinking water and people of this region. Denison, which has staked 110 claims around the Grand Canyon, is seeking groundwater-aquifer permits that would allow it to reopen the Canyon Mine, near Red Butte on the South Rim, as well as two other mining sites. Uranium mining has been associated with contamination of ground or surface water. Here, mining could poison the aquifer, which extends for 5,000 square miles under the Coconino Plateau, and serves as drinking water for our tribe and neighboring communities. As I told Congress recently, if our water were polluted, we could not relocate to Phoenix or someplace else and still survive as the Havasupai Tribe. We are the Grand Canyon. Thanks to Arizona Congressman Raul Grijalva for introducing the Grand Canyon Watersheds Protection Act.
    [Show full text]
  • Mid-Scale Drivers of Variability in Dry Mixed-Conifer Forests of the Mogollon Rim, Arizona
    Article Mid-Scale Drivers of Variability in Dry Mixed-Conifer Forests of the Mogollon Rim, Arizona Matthew Jaquette 1, Andrew J. Sánchez Meador 1,* , David W. Huffman 2 and Matthew A. Bowker 3 1 School of Forestry and Ecological Restoration Institute, Northern Arizona University, Flagstaff, AZ 86011, USA; [email protected] 2 Ecological Restoration Institute, Northern Arizona University, Flagstaff, AZ 86011, USA; [email protected] 3 School of Forestry, Northern Arizona University, Flagstaff, AZ 86011, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-928-523-3448 Abstract: The structure and composition of southwestern dry mixed-conifer forests have changed sig- nificantly, decreasing forest resiliency to uncharacteristic disturbances which also threaten ecosystem services. Restoration of these forests can be informed by historical conditions; however, managers and researchers still lack a full understanding of how environmental factors influence forest conditions. We investigated historical and contemporary variability in dry mixed-conifer forests in northern Arizona and identified important environmental drivers. We utilized forest sample plots and den- drochronological reconstruction modelling to describe forest conditions in 1879 and 2014, respectively. We used correlogram analysis to compare spatial autocorrelation of average diameter, basal area and tree density, and structural equation modeling to partition the causal pathways between forest structure, forest composition, and a suite of environmental factors reflecting climate, topography, and soil. Historical (1879) reconstructed forests had significantly fewer trees, lower basal area, and Citation: Jaquette, M.; Sánchez Meador, A.J.; Huffman, D.W.; Bowker, higher average diameter than contemporarily (2014). Composition has shifted from ponderosa M.A. Mid-Scale Drivers of Variability pine dominance towards a more mixed-species composition.
    [Show full text]
  • Hydrogeology of the Chinle Wash Watershed, Navajo Nation Arizona, Utah and New Mexico
    Hydrogeology of the Chinle Wash Watershed, Navajo Nation Arizona, Utah and New Mexico Item Type Thesis-Reproduction (electronic); text Authors Roessel, Raymond J. Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 07/10/2021 19:50:22 Link to Item http://hdl.handle.net/10150/191379 HYDROGEOLOGY OF THE CHINLE WASH WATERSHED, NAVAJO NATION, ARIZONA, UTAH AND NEW MEXICO by Raymond J. Roessel A Thesis Submitted to the Faculty of the DEPARTMENT OF HYDROLOGY AND WATER RESOURCES In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE WITH A MAJOR IN HYDROLOGY In the Graduate College THE UNIVERSITY OF ARIZONA 1994 2 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author.
    [Show full text]
  • Geologic Influences on Apache Trout Habitat in the White Mountains of Arizona
    GEOLOGIC INFLUENCES ON APACHE TROUT HABITAT IN THE WHITE MOUNTAINS OF ARIZONA JONATHAN W. LONG, ALVIN L. MEDINA, Rocky Mountain Research Station, U.S. Forest Service, 2500 S. Pine Knoll Dr, Flagstaff, AZ 86001; and AREGAI TECLE, Northern Arizona University, PO Box 15108, Flagstaff, AZ 86011 ABSTRACT Geologic variation has important influences on habitat quality for species of concern, but it can be difficult to evaluate due to subtle variations, complex terminology, and inadequate maps. To better understand habitat of the Apache trout (Onchorhynchus apache or O. gilae apache Miller), a threatened endemic species of the White Mountains of east- central Arizona, we reviewed existing geologic research to prepare composite geologic maps of the region at intermediate and fine scales. We projected these maps onto digital elevation models to visualize combinations of lithology and topog- raphy, or lithotopo types, in three-dimensions. Then we examined habitat studies of the Apache trout to evaluate how intermediate-scale geologic variation could influence habitat quality for the species. Analysis of data from six stream gages in the White Mountains indicates that base flows are sustained better in streams draining Mount Baldy. Felsic parent material and extensive epiclastic deposits account for greater abundance of gravels and boulders in Mount Baldy streams relative to those on adjacent mafic plateaus. Other important factors that are likely to differ between these lithotopo types include temperature, large woody debris, and water chemistry. Habitat analyses and conservation plans that do not account for geologic variation could mislead conservation efforts for the Apache trout by failing to recognize inherent differences in habitat quality and potential.
    [Show full text]
  • I2628 Pamphlet
    U.S. DEPARTMENT OF THE INTERIOR TO ACCOMPANY MAP I–2628 U.S. GEOLOGICAL SURVEY Version 1.0 GEOLOGIC MAP OF THE LITTLEFIELD 30' × 60' QUADRANGLE, MOHAVE COUNTY, NORTHWESTERN ARIZONA By George H. Billingsley and Jeremiah B. Workman INTRODUCTION 10 km north of the north-central part of the map and are the largest settlements near the map area. This map is one result of the U.S. Geological Survey’s Interstate Highway 15 and U.S. Highway 91 provide intent to provide geologic map coverage and a better under- access to the northwest corner of the map area, and Arizona standing of the transition in regional geology between the State Highway 389 provides access to the northeast corner. Basin and Range and Colorado Plateaus in southeastern Ne- Access to the rest of the map area is by dirt roads maintained vada, southwestern Utah, and northwestern Arizona. Infor- by the U.S. Bureau of Land Management, Arizona Strip Dis- mation gained from this regional study provides a better trict, St. George, Utah. The area is largely managed by the understanding of the tectonic and magmatic evolution of an U.S. Bureau of Land Management, the Arizona Strip Dis- area of extreme contrasts in late Mesozoic-early Tertiary trict, which includes sections of land controlled by the State compression, Cenozoic magmatism, and Cenozoic extension. of Arizona. There are several isolated sections of privately This map is a synthesis of 32 new geologic maps encom- owned lands, mainly near the communities of Littlefield, passing the Littlefield 30' x 60' quadrangle, Arizona. Geo- Beaver Dam, and Colorado City.
    [Show full text]
  • Late Wisconsin Climate Inferences from Rock Glaciers in South-Central
    LateWisconsin climatic inlerences from rock glaciers in south-centraland west-central New Mexico andeast-central Arizona byJohn W. Blagbrough, P0 Box8063, Albuquerque, NewMexico 87198 Abstract Inactive rock glaciersof late Wisconsin age occur at seven sites in south-central and west-central New Mexico and in east-centralArizona. They are at the base of steep talus in the heads of canyons and ravines and have surfacefeatures indicating they are ice-cemented (permafrost) forms that moved by the flow of interstitial ice. The rock glaciersindicate zones of alpine permafrost with lower levels that rise from approximately 2,400m in the east region to 2,950 m in the west. Within the zones the mean annual temperaturewas below freezing, and the climatewas marked by much diurnal freezing and thawing resulting in the production of large volumes of talus in favorableterrain. The snow cover was thin and of short duration, which fa- vored ground freezing and cryofraction. The rock glaciers in the east region occur near the late Wisconsin 0'C air isotherm and implv that the mean annual temperature was depressedapproximately 7 to 8'C during a periglacial episodein the late Wisconsin.A dry continental climate with a seasonaldistribution of precipitation similar to that of the present probably prevailed, and timberline former timberlines. may have been depresseda minimum of 1,240m. The rise in elevation of the rock glaciersfrom east to west acrossthe region is attributed to greater snowfall in west-centralNew Mexico and east-centralArizona, which reducedthe inten- sity and depth of ground freezing near the late Wisconsin 0"C air isotherm.
    [Show full text]
  • Tertiary Stratigraphy of the Navajo Country Charles A
    New Mexico Geological Society Downloaded from: http://nmgs.nmt.edu/publications/guidebooks/9 Tertiary stratigraphy of the Navajo country Charles A. Repenning, J. F. Lance, and J. H. Irwin, 1958, pp. 123-129 in: Black Mesa Basin (Northeastern Arizona), Anderson, R. Y.; Harshbarger, J. W.; [eds.], New Mexico Geological Society 9th Annual Fall Field Conference Guidebook, 205 p. This is one of many related papers that were included in the 1958 NMGS Fall Field Conference Guidebook. Annual NMGS Fall Field Conference Guidebooks Every fall since 1950, the New Mexico Geological Society (NMGS) has held an annual Fall Field Conference that explores some region of New Mexico (or surrounding states). Always well attended, these conferences provide a guidebook to participants. Besides detailed road logs, the guidebooks contain many well written, edited, and peer-reviewed geoscience papers. These books have set the national standard for geologic guidebooks and are an essential geologic reference for anyone working in or around New Mexico. Free Downloads NMGS has decided to make peer-reviewed papers from our Fall Field Conference guidebooks available for free download. Non-members will have access to guidebook papers two years after publication. Members have access to all papers. This is in keeping with our mission of promoting interest, research, and cooperation regarding geology in New Mexico. However, guidebook sales represent a significant proportion of our operating budget. Therefore, only research papers are available for download. Road logs, mini-papers, maps, stratigraphic charts, and other selected content are available only in the printed guidebooks. Copyright Information Publications of the New Mexico Geological Society, printed and electronic, are protected by the copyright laws of the United States.
    [Show full text]